Lumber-tester.



0.1. ZIGLER @L w. P. HOLDEN." LUMBER TESTER.

APPUCATON FILED MAY||| 1914 1,223, l 32., Patented Apr. 17, 1917.

[Illll Y MV lbefore being used for manufacture.

UNITED srA'rEs PATENT oEEIoE.

oHAELEs J. ZIGLEE AND WILLIAM I. HOLDEN, or CHICAGO, ILLINOIS.

LUlVIBER-TESTER.

It is well understood that lumber or-timber should be properly dried or seasoned This drying may be done in any desired manner, but for commercial purposes it 1s usually done in kilns. It is perhaps not so well understood that lumber vshould not be too thoroughly dried, otherwise it is apt to swell when put into use. The present invention relates to 4means for testing lumber whereby the amountof shrinkage or swelling which such lumber is apt to undergo after being put into use may be readily determined. This improved device and means of testing also determines the percentage of moisture in the lumber to an exceedingly exact degree, and as the common practice is to give the result of tests in percentages of moisture, we provide means whereby such percentage may be readily determined by means of our improved testing device.

Among the objects of this invention are to produce a simple and efcient device of 1 this character, which will be exceedingly accurate in its operation and to provide means whereby anyone, even with little or no skill in testing, may readily determine the conditiony of the lumber to be tested. In the accompanying drawings illustrating our invention:

Figure 1 is a side view of the device shown in position when first applied to a test piece;

Fig. 2 is asimilar view showing the device applied to a test piece after the same has been thoroughly dried;

. Fig. 3 is an edge or front view of the device- Fig. 4 is a view showing the opposite side of the device from that shown in Fig. 1; and

Fig. 5 is a cross sectional view.

The particular form of device shown in these drawings comprises a member 6 made substantially in the form of a square having a long leg or branch 7 and a short leg or branch 8. A slide 9 is mounted uponthe leg 7 and may be held in adjusted position n by means of a set screw 10. This slide is Specication of Letters Patent.

Patented Apr. 17, 1917.

Application filed May 11, 1914. Serial No. 837,679.

preferably made of two side plates 11 and 12, which are grooved on their inner surfaces to form openings for the leg 7 and a pin 13. These two side members are flastened together by means of rivets 14. i This provides an economical method of construction for such slide and permits it to be made very accurate. The pin 13 is considerably longer than the slide'and is freely movable through the hole provided for the same. This pin is preferably made with a head 14 which is flattened on one side to engage with the edge of the leg 7 to form p a guide forv the pin and also to prevent its turning. A set screw 15 extends from the side of the slide 11 and 'engages with the pin 13 for holding it in adjusted position. The leg 7 may be provided with a scale as shown in Fig. 4 so that the device will also serve for ordinary measurements. On the opposite side of 'this' leg, as indicated in Figs. 1 and 2 are a number of divisions marked to indicate percentages of moisture. From a long and exhaustive study of the testing of woods, we have discovered that, within a reasonable limit, the total amount of shrinkage in a test piece, when measured across the grain of the wood7 is dependent upon the percentage of moisture in the piece. We have also discovered that the shrinkage of all different kinds of wood such as ordinarily'used for commercial purposes, is the same for a given amount of Amoisture contained therein. 'From these tests we provide the shrinkage dimensions shown upon the device in Figs. 1 and 2 to indicate certain percentages of moisture. Any number of these dimensions may be provided, but the ones shown are suliicient for ordinary testing purposes. These dimensions were obtained by taking a large number of test pieces ofthe width, across the grain, most commonly used, approximately six inc-hes, and comparing the shrink- A age of these test pieces with the percentage of moisture contained in such test pieces. In other words, takinga large number of test pieces all having the same percentage of water contained therein, which could be determined by weight, it was found that all of such test pieces shrank across the grain thereafter safely be used for the purpose of indicating that a test strip contained 1-1 per cent. of water when it was found to shrink 2; of an inch upon drying. 1n this manner the various dimensions shown in Figs. 1 and 2 were determined and applied to the scale, and after having thus once determined these dimensions, the measurement of shrinkage would thereafter serve for the purpose of determining the percentage of moisture by comparing the amount of shrinkage with such dimensions. Having the complete device, with the percentage dimensions indicated thereon, the operator selects a piece of lumber, preferably from about the center of the car or pile which is to be tested. The test piece is preferably cut from the center, or some distance from the end of the board in order to make the test as accurate as possible. The test piece is cut about gg of an inch to of an inch long and across the full width of the board. 1f the test piece is too wide (across the grain) to go into the tester, the operator then cuts olf about 6 to 8 inches and squares up the ends of the piece and places it in the device in the position shown by the piece 15 in Fig. 1. The slide 9 is moved up till it engages closely with the end of the piece, so asto give an accurate measurement of the width thereof, but the pin 13 is released so that it does not project from the side of the slide. The set screw 10- is then tightened, which holds the slide in position, and the test piece 15 is removed. This piece is then\dried until it is bone dry, by being placed on a hot plate or in any desired manner to thoroughly drive the moisture therefrom. It is preferable to turn the test piece so that it will not warp when drying. After the test piece has been thoroughly dried, it is allowed to cool and again placedin the testing device, as shown in Fig. 2. The driving of the moisture from the test piece will cause it to shrink so that its width will not be as great as when 1n its-first condition, so that if the end of the test piece is placed against the branch 8, there will be a space between the opposite end and the slide 9. The operator then advances the gage pin until it touches the wood, as shown in Fig. 2. The pin 13 is then secured in position by means of the set screw 15. The test piece is then removed from the device and the set screw 10 loosened and the gage block moved along as indicated in dotted lines in Fig. 2, until the distance which the pin projects from the edge of the slide corresponds with one of the percentage dimensions shown on the device. The pin is arranged as close to the edge of the bar 7 as possible, for convenience in making thiscomparison. The percentage marked at such dimension will show the operator the percentage of moisture in the piece tested.

For ordinary commercial purposes, 3 to 5 per cent. of moisture may be permitted without danger' of the wood shrinking too much for satisfactory use, and for finer work, such as cabinet work, 2 to 3 per cent. of moisture may be permitted, these allowable limits being shown on the device for the convenience of the operator.

Attention is called to the fact that a per cent. of moisture, less'than a given amount,

say 2 per cent., is undesirable because the wood is apt to swell when placed in use.

From this description it will be seen that we provide a new method of testing the per cent. of moisture in lumber by testing the shrinkage thereof, and also provide a convenient and eflicient device for making such tests. The necessity of testing lumber is so well understood that it need not be elaborated upon. lt will be observed that our improved testing device may be made in various forms in order to accomplish the desired result, without departing from the scope of this invention, which relates broadly to the means for determining the shrinkage, and therefore we do not wish to limit ourselves to the exact form or device shown and described, except as specified in the following claims, in which we claim:

l. A new article of manufacture, cornprising a lumber tester consisting of a plate having markings thereon in pairs, the marks of each pair being separated a distance corresponding to the amount that a test-piece having a standard dimension and which originally contained a given percentage of moisture, will shrink in drying, the different pairs being for different percentages which are indicated in each case by suitable markings adjacent the respective pairs, and means for measuring the shrinkage of a test piece and for comparing the measurement with such graduations, in order to determine the percentage ofinoisture in the piece tested.

2. A lumber tester comprising a bar having a plurality of measurements marked thereon, each of such measurements having a numeral associated therewith, representing the percentage of moisture which a standard sized test piece originally 'contained if such test piece, upon drying, shrank an amount corresponding to the respective measurement, and means for measuring the shrinkage of a test piece and for comparing such shrinkage with the respective measurements of the bar.

3. A lumber tester comprising a square having a plurality of graduations marked in pairs adjacent a longitudinal edge on one arm thereof, the marks of each pair being separated a distance corresponding to the amount that a test-piece having a standard dimension and which originally contained a given percentage of moisture, will shrink in drying, the different pairs being for dif- Jferent percentages which are indicated in each case by suitable markings adjacent the respective pairs, a slide on said arm, means for locking said slide, an adjustable pin in said arm, arranged adjacent to the edge of the arm having the graduations thereon, and means for locking said pin, the arrangement being such that the shrinkage of a test piece may be indicated by the protruding portion of the pin, and this portion of the pin be moved along the arm to compare its length with the distance separating the pairs of graduations.

4. A scale for indicating percentages of moisture in Wood, said scale comprising a body having a series of distances varying in length marked thereon, each distance being dened by tvvo marks denoting the limits of that distance, and each distance being marked by a numeral representing'v percentage of moisture originally in a standard test piece Which shrinks an amount corresponding to the distance so marked.

CHARLES J. ZIGLER.

WILLIAM P. HOLDEN.

Witnesses:

WILLIAM C. J. Urns, CATHERINE McGrINN.

Copies of this patent may be obtained for ve cents each, by addressing the Commissioner of Patents,

' Washington, D. C. 

